Is there any way to downgrade a project from the current beta???

I just tried to download the little app, but Windows won't let me install it.  Says "Smart Screen" is blocking the unknown app. Have a client who wants a project file but doesn't have the beta.

I uploaded it further down in the thread. My bad, I meant it to be a direct reply to you.

I tried to recreate the issue by opening the same file and replacing the source footage back to the mkv file. The frame errors weren't present this time because maybe I was able to render the footage with the mp4? Previously when I tried to render the files Premiere Pro would just crash half way through. It is the later half of the footage as well where you can see some issues persisting such as looping audio. At the end of the footage you can see me change it back to mp4 and it works without issue again. This is in the version 26 beta currently because I don't plan on using beta again after this, ha. Don't know if version 27 already fixed the problem.

Thank you! I'll try to use this for the other 2 projects I lost and see if I can recover them. Thank you!

@boracayb26418605 I'm sorry about the project upgrading issue. There was a bug in Premiere Pro 25.6 that would update your project format. Now if you're on 25.6.1 or 25.6.2, it won't be able to open that project.

We've written a little downgrader tool that can take your unintentionally upgraded project and restore it so it'll work in the current versions of Premiere Pro (like 25.6.2). You can get it here: https://community.adobe.com/t5/premiere-pro-bugs/p-premiere-projects-saved-in-v25-6-0-cannot-be-opened-in-other-v25-x-versions/idi-p/15589164

Ok, thank you for the additional information. We'd very much like to understand the issue so we can get it resolved and you won't have to continue to convert those files. Would you be able to provide us with a sample clip that reproduces the issue? 

Yep! That was one of the first solutions I tried, nothing worked. And I have been previously using mkv without issue both in current and beta Premiere Pro. Just this morning I went to continue that work and that was when I was getting obliterated with frame substitution and recursion errors when it was just fine the afternoon before on 11/23. Converting the files to mp4 have no issues and the preview panel is fine even without rendering. I'm just happy I'll be able to finish my current work.

I don't have an answer to the project downgrade question here so I'll leave that to others that are more familiar with that area of PPro. Where I am concerned though is the MKV issues you're seeing. I'm glad you were able to convert the files and get back to a working state, but I would expect MKV to work. Did these MKV files use to work prior to the unintended update? My thinking here is that maybe there is a problem with some media cache confusion. IF that is the case, then the easy solution is to go in to the Premiere Pro preferences > Media Cache and delete it. If that does not resolve the issue, I'd be happy to have one of our developers take a look at a sample file and see if we can determine why. 

EDIT: In case anybody has similar issues I converted the source file from mkv to mp4 and it seems to have fixed the issue. Phew. I'm finishing this project and from now on I'm making sure I don't get baited into using the beta. (Though I know using mkv is not the best idea from the start)

Addendum: Prior to the issue it was working fine just hours ago then it went kaput on both the hardware I worked on and my desktop with a stronger setup.